Direct reading comfortable temperature indicator



F b. 23, 1937. w. SHURTLEFF 0 DIRECT READING COMFORTABLE TEMPERATURE INDICATOR OriginalFiled Dec. 29, 1930 WINTER.

Patented Feb. 23, 1937 Q DIRECT READING COlVlFORTABIJE TEMPERATURE INDICATOR Wilfred 'Shurtleif, Moline, 111., assignor to The Herman Nelson Corporation, Moline, 111., a corporation of Illinois Original application December 29, 1-930, Serial No. 505,294. Divided and this application June 3,1935, .Serial No. 24,598

4 Claims. (Cl. 73--.24)

This invention relates to direct reading com- Referring to the accom anying drawingfortable temperature indicators. Figure 1 is a front view in elevation of a modi- In using the term comfortable temperature fled type of instrument employing the principles or effective sensible temperature", it is intended of my invention; and

, to refer to that condition resulting from the com- "Fig. 2 is a rear view of the structure shown in 5 bination of dry bulb temperature and relative Fig.1. humidity, which is considered to be conducive This is a division of my (JO-pending application to physical comfort, as distinguished from dry Serial No. 505,294, filedDece ber 29, 1930, which bulb temperature without reference to relative has resulted in Patent'No. 2,010,040, granted humidity, and as distinguishedjfrom relative hu- August 6, 1935. lo midity without reference to dry bulb tempera- As 'hereinbefore stated, it is well known that ture. the conditions in an inhabited zone or room are It is well recognized that comfortabletemperaaffected "by both the, dry bulb temperature and tures are governed toallarge degree by-the relathe relative humidity, and that within a certain tive humidity of the air, and not merely by the range the combinations of dry bulb temperature 5 temperatures indicated by the so-called dry bulb and relative humidity are productive of results thermometers. Experiments have shown, for which are considered comfortable temperatures. instance, thata-given dry bulb temperature 'com- Deviations of one of the factors in this comfort monly thought to be desirable for physical comzone or range, should be compensated for by a fort becomes very uncomfortable when the relacorresponding change of the other factor to protive humidity is increased, and, :on the other vide a combination which is sensibly comfortable. hand, agiven dry bulb temperature commonly For instance, assuming a dry bulb temperature considered undesirable for physical comfort may of 72 provides an ideal or'desirable comfortable be :made comfortable by an increase or decrease temperature only when the relative humidity is in the relative humidity. about 5'0%. If for any reason the relative hu- Dry bulb thermometers have been in use and midity at this dry bulb temperature should inare commonly known asindicators of dry bulb crease to, say, 90%, a comfortable temperature temperature. These -'thermom'eters include many could still be maintained by correspondingly redifierent types of materials responsive to changes ducing the dry bulb temperature to, say, 67. In in dry bulb temperature, all of which give no inotherwords, the comfortable temperature with d dication of the relative humidity which is so imthis change in both factors would be sensibly the portant a factor in the cornlit-ion which effects same as when the condition consisted of a d y comfortable temperatures. Devices or lnstrubulb temperature of 72 with a relative humidity ments for measuring moisture conditions, 01"1'91? of 50%. In controlling room conditions, it is 5 ative humidity, are also available. With the demore practical to vary the dry bulb temperature vices available attempts have been made to use by regulating the heating meansin the room to an aggregation of a dry bulb thermometer and conform the'dry bulb temperature to whatever a Wet bulb ty thermometer ide by side, conditions of relative humidity may exist at the and, by the use of a chart in connection with the ti e, 40 individual readings of these instruments, deter- Since in my present invention the readings or 40 mine whether the particular condition representindications are those of the resultants of the two ed by these two readings is within the range of component factors which make up comfortable comfortable temperatures. All of the attempts temperature, the instrument is of particular adalong these lines are naturally too complicated vantage as a means for checking the regulating for the layman to determine whether the particudevices which are used for varying the dry 45 lar condition is within the range of comfortable bulb or relative humidity conditions to maintain temperatures. the desired comfortable temperature.

The object, therefore, of this invention, is to In the instrument shown in Fig. 1, an ordinary provide an indicating instrument which is jointly or usual type dry bulb thermometer A, responsive 7 5O responsive to both dry bulb temperature and relto dry bulb temperature, is fixedly mounted upon ative humidity and arranged to directly indicate a suitable base B by means of the clips 25 at its the resultant or combination of the two factors upper and lower ends. This thermometer has producing this resultant or combination. the usual bulb 26 at its lower e1 1d and a column of Other objects of the invention will appear heremercury or colored alcohol 21 in the tube thereof,

inafter. the rise and fall of the level 28 of said column 55 of liquid indicating the temperature variations. In this structure the calibrated scale 29 is given movement relatively to the dry bulb thermometer by means of the humidity responsive element. The scale preferably consists of a flat plate adapted to slide vertically on the front surface of the base B. It is provided with open-ended slots 30 at its upper and lower ends to clear the clips 25 holding the thermometer A in position. The

scale is positioned between the base and the thermometer and has a rearward hook 29' at its upper end portion which extends through an elongated slot 3| in the base. This clip engages the humidity responsive element 32 which extends across the back of the base and parallel thereto, the arrangement being such that the scale is hung or suspended from the center of this member 32 by the hook member 29. element 32 is preferably in the form of a plurality of strands of hair which are extended between two outstanding screws or studs 33 on the back of the base and are anchored to these screws. By rotating one or both of the screws, the sag or catenary of the strands of hair can be varied to accurately position the suspended scale relatively to the dry bulb thermometer. Strands of human hair are very effective for this purpose because of the well known properties of hair which cause it to change its length with variations in humidity. The scale 29 is provided with numerals 34 and calibrations 35. In like manner, the scale is also provided with the heavy mark 36 indicating the comfort zone, thus making the instrument direct reading so that the relative movement of the scale and column of liquid in the thermometer in response to the dry bulb temperatures and humidity conditions may be directly observed in terms of degrees on the scale.

On the face of the base are two arrows 37 designated Winter and Summer, these arrows being positioned adjacent the top edge of the movable scale. The position of the top edge of the scale, with respect to these arrows, serves to indicate at a glance whether the instrument is properly adjusted in a rough way: that is, in the winter season the sag or catenary should be adjusted to position the top edge of the scale near the arrow marked Winter, and in the summer I season near the arrow marked Summer. This provides a coarse adjustment of the instrument for each season of the year. The reason for this coarse setting is that in the summer the air humidity is nearly always between 60% and 100 and in winter the humidity is between and 40%, or quite dry.

Thus it will be seen that I have provided a de- The humidity responsive ing strands of hair secured to spaced members so as to be movable by contraction and expansion in responseto humidity variations, and a movable scale suspended on said strands of hair and positioned in juxtaposition to the movable means of said temperature responsive device for indicating the resultant of the relative movement of said scale and temperature responsive movable means.

2. A device of the character described, comprising a plurality of means supported on a base, one of which is a liquid thermometer carried on the base and responsive to dry bulb temperature conditions, and the other of which comprises hair secured to spaced members on the base to form horizontal strands responsive to humidity conditions, and a scale carried by the strands of hair and calibrated in degrees of effective sensible temperature, saidi scale cooperating with the thermometer to indicate therewith a resultant of the temperatureand humidity responses.

3. A device of the character described, comprising a liquid thermometer means responsive to dry bulb temperature conditions, a scale means, a base having spaced supports, a strand of hair responsive to humidity conditions and carried on the supports, one of said means being carried by the base while the other is suspended on the strand of hair, the scale being calibrated in degrees of efiective sensible temperature, said scale cooperating with the thermometer to indicate therewith a resultant of the temperature and humidity responses.

I 4, Ina device of the character described, the combination of a scale slidable on a support and calibrated in degrees of effective sensible temperature, actuating means for moving said scale comprising strands of hairas an element responsive to variations in moisture conditions, said strands being secured to fixed spaced members to form a horizontal strand, the scale being attached to the strand substantially midway of the latter, a liquid element responsive to variations in dry bulb temperatures and arranged to indicate said variations on said scale in relation to the movement of the scale by said actuating means, and means for tensioning the strands for adjusting the position of said scale relative to the liquid element.

I Y WILFRED SHUR'I'LEFF. 

